AM Solomani Calibration Point.

[aramis]

Due to another thread, I got thinking about the calibration point established by the Terrans getting to Barnard's star.

Doing the back of the envelope on the ship:
A Bk2 version
020 Bridge
001 Model 1
010 JD A*
001 MD A*
004 PP A*
010 J1 fuel
010 P1 fuel
016 4x SR
028 Mission capacity*
====
thing burns 15Td per jump (counting a week maneuver time; 3 days on either side). It can carry just shy of 3 jumps if it is in pure range mode...
That's jump out, drop a cargo tank, jump back. (13Td spare, and we'll drop that to 12Td to allow for 1Td of batteries and a 1L transponder beacon.)

call it a 4 week cycle, to allow for admin oversight and maneuver to match up to prior drops.

Cycle 1 results in a 12 ton store
Cycle 2 has 24 tons
Cycle 3 has 36 tons
Cycle 4 is the jump to the far side, refilling the 15 tons used from the cache (leaving 20)
Cycle 5 is the return from the far side, pulling another 15 tons, leaving 5 in the cache. Probably less, actually, as the fuel will lose a bit by hydrogen tunneling.
that's a 5 month run.


Now, looking to bk 5 designs...
020 Bridge
001 Model 1
002 JD 1
004 PP 1
001 MD 1
016 Computer
001 PPFuel
010 JFuel
045 mission cargo
===
10.5 Td fuel per two weeks of jump;
21 Td per 4 week cycle (2 jumps)

ship has 2 cycles aboard
out for one cycle, operate for one cycle, and back for one cycle, giving 2Pc range, with an additional weeks of science loiter fuel possible.
It really can hit 5J1.

 

[OIT]

For the Book 2 design, why not go up to a slightly larger, non-standard hull size so you can avoid the deep space refueling:

120-ton custom hull
20 Bridge
15 Drives (PP A, M A, J A = P1/M1/J1)
68 Fuel (8 weeks PP operation and four successive J-1)
2 Computer-2
12 Three Staterooms (double occupancy, Pilot, Nav, Eng, Medic, 2 Mission Specialists)
1 Turret (Missile Launcher for launching atmospheric/planetary probes)
2 Emergency Low Berths (because we at NASA care about you, our astronauts)

The hull would cost 10MCr more than the standard 100ton design, but would turn the five month trip to a seven week trip - and that includes three weeks on station for exploration.

The book 5 design works, except the computer tonnage looks awfully high (should that line be staterooms?) and IIRC the maneuver drive should be 2%.